Bug#909128: gcc-defaults: debian/rules control duplicates amd64 compilers when regenerated on arm64 hosts

[Alex Bennée <alex.bennee@linaro.org>]

Source: gcc-defaults
Version: 1.179
Severity: normal

Dear Maintainer,

If you run debian/rules control on an arm64 machine dpkg barfs warning
about duplicate *-x86-64-linux-gnu packages causing the build to fail.
This is probably due to clashing special casing for the amd64
packages.

A simple patch to fix this is:

--- gcc-defaults-1.179/debian/rules     2018-08-16 10:44:12.000000000 +0000
+++ gcc-defaults-1.179-ajb/debian/rules 2018-09-18 18:30:03.621593507 +0000
@@ -366,7 +366,7 @@
         $(if $(filter $(DEB_HOST_ARCH), i386 x32), amd64) \
         $(if $(filter $(DEB_HOST_ARCH), amd64 x32), i386)
     else ifeq ($(DEB_HOST_ARCH),arm64)
-      CROSS_ARCHS = amd64 armel armhf i386
+      CROSS_ARCHS = armel armhf i386
     else ifeq ($(DEB_HOST_ARCH),ppc64)
       CROSS_ARCHS = ppc64el
     else ifeq ($(DEB_HOST_ARCH),ppc64el)

This is a problem as amd64 is always added to the build in:

ifeq ($(with_cross),yes)
        : # FIXME: filter-out some gdc and gccgo multilib configs
        $(foreach a,amd64 $(CROSS_ARCHS), \

I think either amd64 shouldn't be in the cross arch filters or shouldn't be
unconditionally added later on. This may apply to other architectures
too and would probably show up if the control files where regularly
regenerated on non-x86 hosts.

Regards,

Alex.